Intestinal CFTR expression alleviates meconium ileus in cystic fibrosis pigs
David A. Stoltz, … , David K. Meyerholz, Michael J. Welsh
David A. Stoltz, … , David K. Meyerholz, Michael J. Welsh
Published May 8, 2013
Citation Information: J Clin Invest. 2013;123(6):2685-2693. https://doi.org/10.1172/JCI68867.
View: Text | PDF
Technical Advance Gastroenterology

Intestinal CFTR expression alleviates meconium ileus in cystic fibrosis pigs

Abstract

Cystic fibrosis (CF) pigs develop disease with features remarkably similar to those in people with CF, including exocrine pancreatic destruction, focal biliary cirrhosis, micro-gallbladder, vas deferens loss, airway disease, and meconium ileus. Whereas meconium ileus occurs in 15% of babies with CF, the penetrance is 100% in newborn CF pigs. We hypothesized that transgenic expression of porcine CF transmembrane conductance regulator (pCFTR) cDNA under control of the intestinal fatty acid–binding protein (iFABP) promoter would alleviate the meconium ileus. We produced 5 CFTR–/–;TgFABP>pCFTR lines. In 3 lines, intestinal expression of CFTR at least partially restored CFTR-mediated anion transport and improved the intestinal phenotype. In contrast, these pigs still had pancreatic destruction, liver disease, and reduced weight gain, and within weeks of birth, they developed sinus and lung disease, the severity of which varied over time. These data indicate that expressing CFTR in intestine without pancreatic or hepatic correction is sufficient to rescue meconium ileus. Comparing CFTR expression in different lines revealed that approximately 20% of wild-type CFTR mRNA largely prevented meconium ileus. This model may be of value for understanding CF pathophysiology and testing new preventions and therapies.

Authors

David A. Stoltz, Tatiana Rokhlina, Sarah E. Ernst, Alejandro A. Pezzulo, Lynda S. Ostedgaard, Philip H. Karp, Melissa S. Samuel, Leah R. Reznikov, Michael V. Rector, Nicholas D. Gansemer, Drake C. Bouzek, Mahmoud H. Abou Alaiwa, Mark J. Hoegger, Paula S. Ludwig, Peter J. Taft, Tanner J. Wallen, Christine Wohlford-Lenane, James D. McMenimen, Jeng-Haur Chen, Katrina L. Bogan, Ryan J. Adam, Emma E. Hornick, George A. Nelson IV, Eric A. Hoffman, Eugene H. Chang, Joseph Zabner, Paul B. McCray Jr., Randall S. Prather, David K. Meyerholz, Michael J. Welsh

×

Figure 1

Intestinal FABP promoter–driven CFTR expression alleviates meconium ileus in CF pigs.

Options: View larger image (or click on image) Download as PowerPoint
Intestinal FABP promoter–driven CFTR expression alleviates meconium ileu...
(A) Schematic of the transgene vector with porcine CFTR cDNA driven by the rat iFABP promoter (nt –1788 to +28), flanked by the intervening sequence and the bovine growth hormone poly-A (BGHpA) and followed by a hygromycin cDNA sequence flanked by SV40 and SV40 poly-A signal sequences. BglI restriction site is denoted. (B) Gross image of a meconium plug (green-black colored portion of stool) that was passed by a CFTR–/–;TgFABP>pCFTR pig (line e) following an enema at approximately 18 hours after birth. A transition to normal-appearing stool (yellow-green stool denoted by arrow) was observed after meconium passage. Scale bar: 2 cm. (C) Images of the gastrointestinal tracts of CFTR–/–;TgFABP>pCFTR piglets. At birth, in 3 of the 5 CFTR–/–;TgFABP>pCFTR lines, meconium ileus was improved. Meconium ileus lesions ranged from improved (left panel, line a) with normal-sized intestine and spiral colon (arrow) to severe meconium obstruction (right panel, line c, white asterisks) often located in the spiral colon with distal microcolon (arrow). Middle panel: gross image from the intestinal tract of a CFTR–/–;TgFABP>pCFTR pig (line a) at 6 days of age. The intestine and spiral colon (arrow) are of normal size and coloration. Scale bar: 1.3 cm.